6. Psycho (1960)
Suffice it to say the Hitchcock game-changer was not based on a motel-owning lunatic with a massive Oedipus complex, but loosely inspired by someone much more insane. Like Hannibal Lecter and Leatherface, Norman Bates was the cinematic spawn of deranged body-snatcher Ed Gein who would rob graveyards in order to score himself some fashion statements of another kind made from bones and skin. When he could not dig out what he needed, he would simply harvest it among the soon-not-to-be living. Unknown if his rituals included fava beans or shower peep-shows, but the use of a chainsaw DOES make sense, kind of.